Isaac weakens, flood threat continues

The National Hurricane Center is tracking Isaac as it moves through Louisiana and Arkansas; image shows path as of Thursday afternoon. (Source:NHC)

Isaac has been downgraded to a tropical depression, but evacuation orders are still in place. (Source: CNN)

High waters at the Tangipahoa River. (Source: WWL/CNN)

A car got stuck when the road dropped off into water in Louisiana. (Source: CNN)

(RNN) - Tropical Depression Isaac weakened further overnight as it moved over southern Arkansas, but heavy rainfall is expected to bring the threat of floods further north.

By 4 a.m. CT Friday, winds from Isaac had continued to decline, slowing to 25 mph. On Thursday, Isaac was reclassified as a tropical depression after winds slowed from early morning highs of 40 mph to 30 mph by the end of the day.

The National Weather Service has issued flood and flash flood watches and warnings to parts of Arkansas, Mississippi and Louisiana and as much as 8 inches of rainfall is expected in the Mississippi River Valley. Parts of Mississippi and Arkansas are on tornado watch as the storm passes through.

Companies have reported that more than 827,000 customers were without electricity in Arkansas, Alabama, Louisiana and Mississippi, according to CNN. That's down from 915,000 on Thursday.

Rescue operations are underway for people trapped in flooded areas of Louisiana and Mississippi, the hardest hit by Isaac. In some cities, residents are taking boats or jet skis to salvage what they can from their flooded homes.

Kenny Fazzio, who owns a home in flooded Kiln, MS, told WLOX that his home had close to five feet of water in it. He left before the flooding started.

"We didn't know what to expect," he said.

Meanwhile, homeowner Johnny Alison said he opted to weather the storm out in his house.

"I just took a boat and walked in the first night because [the water] was only down to my knees," he told WLOX. "By five that morning [the water] was waist high."

Isaac related deaths

While some residents try to salvage their property, at least four Americans have not been so lucky.

A couple was found floating in 7-feet of water at a home in Plaquemines Parish, LA, on Thursday, CNN reported. The couple, who was in their 40s, will undergo an autopsy to determine their cause of death.

A tow truck driver died Thursday in Picayune, MS, when a tree fell on his truck after responding to a call of an abandoned car.

According to the Associated Press, Gregory Alan Parker, 62, had gone out to tow a pickup truck that was stuck in a ditch and abandoned by its driver. Parker reportedly decided it was too muddy and the wind was too strong to attempt the tow.

A man in Vermilion Parish, LA, fell approximately 18 feet after climbing a tree for an unknown reason on Tuesday, the Vermilion Parish Sheriff's Office said. He and two friends had gone to move a car that was under a tree ahead of Isaac when it was still classified as a hurricane.

His identity has not been released.

The Haitian government has said at least 24 people have died in Haiti as a result of Isaac. Multiple deaths have also been reported out of the Dominican Republic after Isaac hit the countries last weekend.

Dams, levees threatened by rainfall

According to WLBT, Lake Tangipahoa at Percy Quin Park is flooding. Its spillways are working, but nearly 10 inches of rain from Isaac created two slides on the side of the dam.

"You don't have as much earth there to keep the water back, essentially and so that's a real threat," said Mississippi Department of Environmental Quality Dam Safety Engineer Dusty Myers.

Louisiana National Guard helicopters are placing boulders on the dam to help ensure it doesn't fail. The Mississippi National Guard was also on the scene with bulldozers and track hoes.

Mississippi Gov. Phil Bryant traveled to Pike County to assess the dam.

"We'll remove some of the roadway and allow some of the pressure of the high water to simply go into the fields, lowering the threat," explained Bryant at a Thursday press conference. The water will go to low lying areas designated in Mississippi, Bryant said.

Louisiana state officials intentionally breached a levee in Plaquemines Parish on Thursday, according to the Associated Press.

The slow-moving storm caused water to start pouring over the top of the Plaquemines Parish levee before daybreak Wednesday.

New Orleans avoided a direct hit, and the city's flood protection system has been holding up, according to the Army Corps of Engineers. The flood-prevention system received an $11 billion upgrade after Hurricane Katrina tore through it in 2005.